EMPEROR PENGUINS ON THIN SEA ICE

Emperor penguins are tough birds that breed on sea ice, which is the frozen surface of the ocean. They are famous for walking across the sea ice, to and from the open ocean, to get food for their chicks. Their bodies and behaviors help them live in the cold, dark winters of Antarctica. However, though they live far away from people, human actions are not always good for emperor penguins. Humans are causing the world to warm. With warmer temperatures, sea ice around Antarctica will melt. For emperor penguins, this means their homes might disappear. We know so much about emperor penguins because scientists and explorers have been studying them for over 70 years. In this article, we will tell you about what is likely to happen to emperor penguins—and what their future can tell us about our own future.

Emperor penguins are tough birds that breed on sea ice, which is the frozen surface of the ocean.They are famous for walking across the sea ice, to and from the open ocean, to get food for their chicks.Their bodies and behaviors help them live in the cold, dark winters of Antarctica.However, though they live far away from people, human actions are not always good for emperor penguins.Humans are causing the world to warm.With warmer temperatures, sea ice around Antarctica will melt.For emperor penguins, this means their homes might disappear.We know so much about emperor penguins because scientists and explorers have been studying them for over years.In this article, we will tell you about what is likely to happen to emperor penguins-and what their future can tell us about our own future.

LIVING ON SEA ICE: A VITAL HABITAT UNDER THREAT
Emperor penguins breed on sea ice, which is the frozen surface of

SEA ICE
Sea ice is frozen water that forms on the surface of the ocean.It is like a big icy blanket that covers parts of the sea when the weather gets really cold.Sea ice is important because it gives some animals a place to rest and hunt, and it also a ects the weather and the whole Earth's environment.the ocean.These birds are specialized to survive in cold conditions that would be too harsh for humans.Emperor penguins have some specific requirements.If there is not enough sea ice, they do not have a place to live.If there is too much sea ice, they have a long walk to get to the open ocean, where they hunt for food for themselves and their chicks.So, the sea ice must be just right for emperor penguins to live, get food, and raise their chicks (Figure and Video ).

Figure
The life cycle of emperor penguins is tied to sea ice (Image credit: Zina Deretsky, National Science Foundation: https: //photolibrary.usap.gov/PhotoDetails.aspx?filename=PENGUIN_ LIFECYCLE_H.JPG).Emperor penguins come to their rookery on a stable sea ice platform in April.In May and June, the mom penguins lay one egg.The dads take care of the egg, keeping it warm, and both moms and dads give food to the baby penguins from August when they are born to November when they are left alone at the colony.The arrows on the map show the path they travel from their home on the ice to the water where they find food.By December, everyone has left the colony.
We know the world is getting warmer and that there might be less sea ice for emperor penguins in the future.The world is warming because humans are producing greenhouse gasses (such as carbon

VIDEO
The life cycle of emperor penguins is tied to sea ice (https:// youtu.be/--JabgZFEjg).

GREENHOUSE GASSES
Gasses like carbon dioxide that trap the sun's heat in Earth's atmosphere, like a blanket of gasses that surrounds our planet and heats it up.dioxide) that trap the sun's heat near the Earth.Greenhouse gasses come from human activities such as burning oil, gas, and coal.The faster the world warms, the less likely emperor penguins are to have sea ice.Will Emperor penguins march to extinction?

SURVIVING THE UNIMAGINABLE
About years ago James Cook, a captain in the British Navy, was sailing around the world.He and his crew may have been the first people to see emperor penguins.What we know for sure is that later, someone noticed that emperor penguins were a di erent species than king penguins [ ].In the early part of the s, Robert Falcon Scott, another captain in the British Navy, sailed to Antarctica.He found the first rookery of emperor penguins.Now, using pictures of the world

COLONY
Animals living together for mutual benefit, such as stronger defense against predators.For emperor penguins, living in colonies is a great defense against the cold and wind.
Even though we have been studying emperor penguins for about years, we still have a lot to learn.These penguins live in dangerous places, and that makes them hard to study.But that has not stopped people from trying.Around years ago, two famous scientists, Bernard Stonehouse and Jean Prévost, visited Antarctica to study emperor penguins.These scientists learned how important sea ice is to these penguins [ ].In the winter when it gets cold, the surface of the ocean freezes.These icy spots on the sea are where emperor penguins gather in special groups to take care of their baby chicks.Those areas are called rookeries or colonies.After forming colonies, the emperor penguins choose their mates in March/ April.The females lay one egg each in May or early June, and the males keep the eggs warm by holding them on the tops of their feet.Males do this for nearly months-and it is not easy!Wintertime in Antarctica is dangerously cold and stormy-temperatures can get down to − • C, and winds can blow at over km per hour.The males must huddle together to keep warm and to survive.The penguins take turns being in the middle of the huddle, where temperatures can reach • C. The penguin dads keep the eggs warm and cozy while the mommies search for food (Figure ).
When the females have eaten enough squid, fish, and krill (shrimp-like creatures), they come back to feed the newborn chicks.The males, which have not eaten in months, are starving by this time.The females take over keeping the chicks warm, while the males search for their own food.Then, mommy and daddy penguins take turns feeding their chick, so the chicks grow up fast and strong.In early spring, the chicks are twice as big as when they hatched, and they can be left on their own.Chicks huddle together to keep warm and to defend each other against other birds species that might attack them, while the parents search for food for a few days at a time.It is hard work raising an emperor penguin chick!Chicks must grow enough to get their waterproof adult feathers before the sea ice melts away for the year.The soft, flu y feathers the chicks have when they are born are not waterproof, so if chicks get wet, they can freeze.From early November, chicks begin to get their adult feathers, and they leave the colony in early summer, from December to January.Without their parents, the chicks hang out together on the ice.

TROUBLING TRENDS
Even though emperor penguins are di cult to study, we have a few clues from a colony found at Pointe Géologie, where they have been studied for a long time.This is where the movie March of the Penguins was filmed!There is a mystery at Pointe Géologie.In the s, the number of emperor penguins decreased from about , birds to about , birds [ ]. Scientists think that many of the adults were dying, and the sea ice was a clue to this mystery.More males died when there was not enough sea ice.Emperor penguins eat animals that live under the sea ice (fish, squid, and krill), and less sea ice probably meant less food.Males need more food than females because they go without eating for months during winter.
Another mystery is that the population of emperor penguins at Pointe Géologie has not yet returned to , birds.Scientists observed that, in years with too much sea ice, fewer chicks survived.Too much sea ice means penguins must travel longer distances to reach open water, where they can find food.So, there is a sea-ice "Goldilocks zone."Too much sea ice means adults take too long to get food, so both adults and chicks may starve.Not enough sea ice means less food for penguins, and chicks may not grow their waterproof feathers before the sea ice melts away.
Today, Antarctica is changing because of greenhouse gasses.Warmer temperatures around the world will cause the sea ice to melt and break up earlier in the spring.Scientists have created computer models

COMPUTER MODELS
Computer-based versions of a natural system, which scientists can use to understand the system and the way that various factors might change the system in the future.
to see what would happen to emperor penguin populations if these penguins have less ice to live on.If we do not change the way we make and use energy, penguins at Pointe Géologie will be at risk of extinction by [ ].
Scientists want to see what will happen to all other emperor penguin colonies, too.Some colonies, such as those in the Ross Sea, might be OK in the future because sea ice declines are less severe at those locations.Sadly, if we continue to put greenhouse gases into the air, all emperor penguin colonies will probably decrease by the year (Figure ).If we keep warming the air, the temperatures around the world will be much higher than we want them to be (increase of .at Halley Bay (Figure a), an estimated , chicks or more died in one year because of very low sea ice.Halley Bay was the world's second-largest emperor penguin colony before this extreme event.Scientists can observe these rare extreme weather events using satellites.At Halley Bay, such satellite images showed that, in , the sea ice broke up early, before the chicks could swim (Figures b-d).By better understanding how extreme weather events a ect penguins, scientists now think that % of colonies will be disappear by if we do not control greenhouse gas emissions-this means that almost all the emperor penguins in the world will be gone.Emperor penguins will only stand a chance if greenhouse gas emissions are slowed from their current course.Satellite images have also helped us understand how colonies might change as penguins move from one spot to another.Does moving between homes mean penguins could find new places to live as the sea ice melts?Scientists initially thought that penguins might leave places that were not good homes and would search for better locations so they could survive.But sadly, it seems that moving between homes does not help, and emperor penguins will still

LIVING ON THIN ICE
Emperor penguins cannot change the way they live fast enough to deal with climate change.So, to save them, humans should reduce greenhouse gas emissions.If we can keep the increase in air temperature around the world to < .• C, emperor penguins will have a better chance of surviving.In , people from countries met in Paris, France and agreed to limit global warming to well below • C.This meeting led to a legal document known as the Paris Agreement.

PARIS AGREEMENT
A plan to reduce greenhouse gas emissions to limit the average global temperature increase.It was signed by nations that agreed to the importance of fighting climate change.This agreement represents the first time that all nations have joined the common cause to fight climate change.Governments must take actions now to reduce greenhouse gas emissions, to protect the Earth and its species for today's and future generations [ ].You can find out more about whether governments are meeting the .Climate change a ects everyone.Today, emperor penguins serve as a signal to show us whether we are e ectively controlling greenhouse gas emissions.They can tell us if we are in danger.We are all on thin ice.The future of emperor penguins, humans, and all other life on Earth as we know it depends upon the decisions we make today.Stephanie is like a bird fortune-teller!She is even been part of important work to make sure the emperor penguin is kept safe.Thanks to her work, these penguins are now protected under a law called the US Endangered Species Act.She worked closely with talented artists to craft captivating illustrations that bring the Emperor Penguin's story to life, you can access and enjoy these vibrant visuals for free right here: https://www .whoi.edu/site/jenouvrier/outreach/exhibits-cartoons/.*sjenouvrier@ whoi.eduMICHELLE LA RUE Dr. Michelle LaRue is an Antarctic marine ecologist at the University of Canterbury (New Zealand) and a research associate at the University of Minnesota (USA).Dr. Michelle has super cool tools in her science kit, like satellite images and photos.With these tools, she learns all about animals in Antarctica.Can you believe she is been to Antarctica eight times?Dr. Michelle is not only a scientist but also a storyteller!She wrote a special book just for kids called "Young Zoologist: Emperor Penguin."

PHILIP TRATHAN
Dr. Philip Trathan is a marine ecologist.Before he retired, Phil was head of Conservation Biology at the British Antarctic Survey (UK).He is now a visiting professor at the University of Southampton.Dr. Philip is like an explorer-he is been to the Antarctic a whopping times!He is not looking for treasure though; he is trying to understand what happens to animals like birds and sea mammals when the climate gets warmer and when people go fishing.His discoveries have been so important that they helped create safe zones, called marine protected areas in the Antarctic and sub-Antarctic.Dr. Philip is like a guardian of the Antarctic ocean!CHRISTOPHE BARBRAUD Dr. Christophe Barbraud is a seabird ecologist at Centre d'Etudes Biologiques de Chizé (France).Dr. Christophe does not just stay in his lab; he is like an adventurer!Every year, he sets o on exciting journeys to gather information about birds and marine mammals.He and his team have been collecting data for several decades!They want to know how things like climate change, fishing, and pollution a ect seabirds and marine mammals.With their smart minds and field trips, they have learned so much!They have even told everyone how climate change can a ect emperor penguins and albatrosses.And guess what?They have helped make sure that fishing does not hurt the seabirds too much.Dr. Christophe and his team are true heroes of the ocean!kids.frontiersin.org

FigureFigure
Figure • C Paris Agreement by looking at the Climate Action Tracker.
trying to understand how climate change and people's actions a ect birds.Dr. Stephanie uses special computer codes to help her figure out what might happen to seabirds as the Earth gets warmer.
disappear.If we can limit global warming to only .•C, emperor penguins will still exist in Antarctica by .Recently, scientists wondered what would happen to emperor penguin colonies if extreme weather events happened.For example, • C above the temperature in ), and most emperor penguin colonies will